A cataract is the clouding of a natural eye lens, the part of the eye that focuses light onto the retina to produce clear, sharp images. The lens is contained in a sealed bag or capsule. As old lens cells die they become trapped within the capsule, and, over time, the accumulation of these cells causes the lens to cloud, so that light is no longer focused properly onto the retina and images appear blurred or fuzzy. For most people, cataracts are a natural result of aging.
A process called extracapsular cataract extraction with implantation of an intraocular lens (IOL) is currently the most common method for the treatment of cataracts. This process involves removing the natural dysfunctional lens and replacing it with an artificial lens. This procedure is less than ideal, however, because the current synthetic IOLs are unable to accommodate appreciably, and secondary opacification of the posterior capsule (i.e. secondary cataracts) is a common occurrence following the procedure.
Importantly, after removal, in some situations eye lenses can regenerate over time. Ideally then, it a regenerated natural lens could replace a suitable biodegradable material, the reformed regenerated lens could have the same or similar natural focusing power as the normal young lens and could be able to accommodate visually. Alternatively, if naturally regenerating lens epithelial cells could be directed to grow in a regularly organized pattern around a suitably flexible and biocompatible polymeric lens, the resultant bilenticular system might also be able to accommodate. Therefore, there is a need in the art for a regenerated lens (with or without a suitably flexible and biocompatible polymeric lens) which would have properties of the natural lens including clarity, protein content, histology, focusing power, spectral transmission, accommodative ability, configuration, shape and structure.
One approach to forming a lens following cataract extraction has been to use accommodative refill lenses. Accommodative refill lenses are created by injecting low viscosity liquids (such as silicone oils or low temperature vulcanizing (LTV) silicone elastomers) into the len's capsular bag through a small incision. After injection, these low viscosity liquids polymerize under forming pressure to create a lens of the required shape. This technique uses the form of the capsular bag as a mold. Various drawbacks associated with this technique remain to date, however, preventing its beneficial use in all patients. The present invention provides beneficial methods of using new materials to create accommodative refill lenses and to enhance natural lens regeneration.